On November 9, 1917, Lenin became the chairman of the newly formed Council of People's Commissars, which replaced the Provisional Government. The most immediate issue was pulling out of the disastrous World War I, which had decimated the Russian army. However humiliating the peace conditions would be, Lenin knew that it would be impossible for his young government to fight the German army. Thus, on March 3, 1918, Lenin signed the Treaty of Brest-Litovsk, in which Russia seceded a large amount of her land and granted Poland, the Ukraine, and the Baltic countries their independence. Summer of 1918 also saw the introduction of War Communism, a new system which officially eliminated all private business and land holdings. The redistribution of food was also central to this new policy, and grain was requisitioned from the peasantry in order to feed the rest of the population.

Leon Trotsky

Also at this time, Russia began to descend into Civil War. The Whites, who believed in the old Tsarist government, as well as other counterrevolutionary forces such as cossacks and army officers, rose to challenge Lenin's Red government. Initially, the Whites succeeded in capturing several of Russia's most important cities, but the Red Army under the direction of Leon Trotsky began to hold them off by 1920. To complicate matters, Poland, the United States, Japan, and much of Western Europe began to fight against the Soviet government, but succeeded in only delivering military supplies to help the White campaign. Poland, however, demanded a return of its «historical lands» in the western Ukraine and Belorussia. This land was awarded to them in 1921, in the Treaty of Riga.

Despite help from the Allied powers, the White army continuously found itself unequipped for war. The Reds had both Moscow and Petrograd, which held most of the country's population and industry. They also had the advantage of the support of the working class, who yet again proved to be helpful in cutting off the communication and transportation of the Whites. By 1918, Civil War died down to Red Victory, yet there was now even more resentment towards Soviet brutality. The country was also decimated, and famine became widespread in both the cities and the countryside. This required drastic action for Lenin, who in 1921 introduced NEP, or the New Economic Policy. This was a brief "sidetrack" to Communism, allowing for small scale capitalism in order for the country to recover with the Soviet government still having ultimate control over the economy. War Communism was also ended, and peasants were incited to produce more grain since they could now enter it into a free market. By 1928, NEP proved to be a great success, and in just 7 years the Soviet Union was able to reach the same levels of industry and production it had before World War I. However, an interesting phenomena grew out of this policy: «Nepmen», the small, independent businessmen that NEP allowed for, and «kulaks», or rich peasants who refused to give over their grain and exploited others, became social targets. Literature of this time especially created the image of Nepmen as the "others," seen especially in Mayakovsky's Vladimir Ilich Lenin and Mystery-Bouffe.

Between 1922 and 1923, Lenin suffered three strokes, which effectively ended his political career. After his first stroke, he wrote his Testament, in which he discussed candidates for his succession. In particular, he warned against the growing power of Joseph Stalin, who initially served a minor role in the party as the General Secretary. This was exacerbated by a later episode in which Stalin spoke profanely to Lenin's wife, apparently telling her that he no longer had to answer to anyone. Lenin then added a postscript to his Testament, advising the party to find a way to remove Stalin from his position.

Kamenev and Zinoviev

After Lenin's death in 1924, Stalin was able to downplay the significance of the Testament by limiting how and when it could to other members of the party. He was helped by fellow politburo members Lev Kamenev and Grigori Zinoviev, who did not want Trotsky to rise to power. However, in order to consolidate his power, he later accused Zinoviev and Kamenev as deviating from the party line, calling only himself the true heir to Lenin's will. These men and countless others would later be put on trial and executed by Stalin, under similar false charges of being "Left deviationist" or followers of Trotsky.